1) A/V control for your television/music system if you want that. That might be phase 2 for you, because typically people are looking for voice control. But some people add motion sensor or pressure Mat control. Or just want the ability to coordinate the lights and the television so that you can, for example, have the television shift to Netflix and the room lights dim to 50%. You would probably use a Logitech Harmony hub ($89 for each television, although depending on your exact requirements you might be able to just use a $35 chrome cast for each television if you use Google home for voice instead of Amazon echo). It integrates well with SmartThings.
2) Some kind of Geopresence so that your house automatically knows when you leave or return. There are several options for that:
3 You might want some handheld or tabletop button remotes just for convenience. These are very popular for those times when you don’t want to use voice control, such as having something on the nightstand that can arm/disarm the security features, turn on some lights, change the mode so the system knows you’re awake, things like that. There are many choices in this category. You might not need any but most people do end up getting one or two.
4 Cameras. these could be for security, as video intercoms, or as video doorbells. These might also be a phase 2 or even phase 3. This is an area where SmartThings is pretty weak, so a lot of people end up not really trying to integrate this into a SmartThings installation. But it’s something most people consider sooner or later. It tends to be one of the more expensive items so it’s good to just be aware that you may want to look into those.
I included video doorbells and video intercoms in this group, but these days most people get purpose built units instead of just another camera for these use cases.
5. smoke alarms I personally don’t recommend making this part of a SmartThings system, but if you do want to add secondary notifications like having the lights flash or the doors unlock if the smoke alarm goes off, there are several ways to do that. Either you get a Z Wave smoke detector or you get an acoustic sensor like the $49 Leeo which will trigger when the hears the nonSmartThings alarms go off and can be integrated with SmartThings through IFTTT. You might also be able to wire A zwave relay into a hardwired smoke alarm system so that the relay can notify SmartThings of activity. And there is also some unofficial possible integration with nest protect, I don’t know much about that one.
Anyway, the point is that if you want full integration, it’s going to affect your selection of the smoke alarms themselves. If you want to integrate through an acoustic sensor, you can just add that later. If you want to try the Z wave really, that doesn’t work with all wiring set ups, so you should research that as soon as possible.
6. Other sensors for temperature, humidity, lights, leaks, vibration, etc. The main point of this is that while the use cases might not come until phase 2, if you think you’re going to want these it will definitely affect device selection in phase 1 because these are the kinds of options that some contact sensors have and some don’t. So it might be worth it to get more expensive phase 1 sensors that can cover the features for these use cases rather than having to buy all new devices for phase 2 sensors.
The following thread covers the different features that different device classes might have.
7. Wearables I just mention this because it can affect device selection. There is unfortunately no real integration at this point between the Samsung gear watch and SmartThings. There’s a very limited integration, essentially the ability to add widgets, to the Apple Watch. But I use my Apple Watch with my automation system a lot, mostly through IFTTT and devices that support HomeKit. It’s just another factor to consider, although it might well be phase 2 or phase 3.
8. Irrigation system. again, probably phase 2 or phase 3, but for a lot of people this is one of the big pluses of whole house Home automation. For technical reasons, this will probably be a zigbee system.
9. Holiday lights. typically Halloween and Christmas, but any holiday where you put up lights can usually benefit a lot from integration with your home automation system in terms of convenience. You can see what other members have done on the holiday project reports list in the quick browse section of the community – created wiki. These are also often projects which have very high family acceptance factor. 
10. Notification Alerts. Anything from “the mail has arrived” to “the laundry is done.” These are popular automation use cases. They typically will require one additional sensor on whatever is being monitored. And then your choice of one or more notifications, such as a push message on your smart watch your phone, A spoken announcement, A light flashing or changing color, A chime, a siren, etc.
I mention this because it’s one of the most popular use cases for an RGBW color changing light, whether it’s a bulb or light strip. And it also tends to have a high family acceptance factor. Most whole house systems will have some of these, how many depends on your own needs and preferences. And, of course, your budget as the cost of these can add up fast.
11. Night lights I only mention this because your list only had zwave light switches on it, and most of those don’t dim low enough for nightlight use cases. LED strips, purposebuilt nightlights like the HSM200, or smart bulbs are more popular for nightlight use cases. So that might be a phase 2, but it could have an impact on some of your phase 1 device selection.
12. Window shades and automated windows. These are expensive, but for some people they are the first thing that they automate. There are a number of different ways to do it and a number of different products that can be integrated with SmartThings, so you don’t have to think about it until you’re ready for that specific use case. But if you’re really talking whole house automation, it is typically part of the project. 
Well, those are just a few more options to consider, I’m sure other people can add additional ones.
Have fun! You might also need the following thread, a lot of us do… 